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Old 09-18-2015, 12:16 PM   #2048 (permalink)
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Originally Posted by MPaulHolmes View Post
That test isn't using regen to slow the motor down. But it would be a good idea.
Oh ... so I wonder why the motor goes into regen (I can feel the torque and the bus voltage goes up when the motor is slowing down)

All it's doing is setting IdRef and IqRef to 300, and letting the motor run as fast as it can. Each rotor time constant candidate gets 5 seconds to do its best RPM, and it just starts at whereever the last guy left off.
From what I have observed ... the motor does does not appear to do this. Between 5 second trials, what is the IdRef and IqRef set to? It looks like maybe -52 amps, to me.

I am not seeing the motor current rising to 300. It appears to rise (consistently) to 42 amps per phase with my clamp-on meter. And it stays there with minor fluctuations during the rotor-test, until we get into the regen stuff ... then it swings from +42 amps to -52.5 amps ... what I had described as 'hunting' before.

If you got a motor overspeed fault when it was set to 10,000, that means that during one of those 5 second times, the motor got to 10000!,
I get overspeed faults pretty consistently when I use max-rpm 6000. I have not gotten overspeed faults at max-rpm 10000 as yet.

and you evidently didn't get to hear about it because of the fault. holy crap.
The controller is backing the motor rpm off .. if it's not your code then maybe the encoder is not rated for 10K rpm? I'll have to check! If your code sees goofy speed signals (or the encoder signal goes away when a wire falls off!) from the encoder, it appears to regen ... like when I had the encoder signal running over the motor to get to the controller, that's what I think was happening. Maybe my encoder is limiting the rotor-test results?

what voltage/current is this motor rated for?
I'll take a picture of the nameplate tonight. EVTV lists 300V and 400A. I think I may have posted these numbers backward before, at a higher voltage and lower amps.

That test is trying to see 44 amps for Id and 44 amps for Iq.
That makes more sense. I see 42 with a clamp-on. I'd believe 44.

Your motor is much more powerful than mine, and the acceleration is more severe. I think I'm going to include a softer ramp, at least for testing. It will make it easier for things to stay under control.
Good! Can you add a condition to the start of the test for each group of settings? If you are over 50% of max-rpm, regen until you get down to 20% or 10% so that you have 'room' for the test to run properly?

I think we may be running out of voltage to apply before the test is complete. Would it make sense to flag each of those tests so we don't use the settings .. since they may be warped or at least not optimal? Perhaps log a warning to the terminal with the voltage, current and speed?

Would it make sense to log an error or warning when the encoder signal jumps? Like we are running at 6K and the next update it seems like the motor is now spinning at 4K? or 8K? You will likely need something like this to track encoder versus Sensorless speed when we get to that part.

... I have such good ideas when I don't have to implement the code!
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